A castle-sized mound of the Balhae Kingdom has been unearthed in Primorsky Kray, Russia. The ruins confirm that Balhae (698-926) stretched even to the 45th to 46th parallels and was the indisputable successor to Koguryo (37 B.C.-668 A.D.).
The National Research Institute of Cultural Heritage made the announcement Thursday. From Sept. 3 until Oct. 2 in cooperation with the history, archeology and folklore research center at the Far Eastern Branch of the Russian Academy of Sciences, the NRICH excavated the ruins of Pyeongji Castle in the Koksharovka-1 area of the Chuguevskiy rayon district east of Lake Xingkai in the Russian Far East.
"In this area, we unearthed lots of relics and large building sites furnished with the 'ondol' floor heating system typical of Balhae," the NRICH said.
The Koksharovka-1 area in the upper reaches of the Ussuri River is 1,645 m long and measures 160,000 sq.m. The castle is well preserved, with the highest point in the ruins being 6 m and the widest point in the castle wall 10 to 14 m.
The NRICH said the castle "is decisive evidence refuting the claim of some Russian scholars that Balhae's northernmost border was south of Primorsky Kray."
